590
FXUS65 KBYZ 291205 CCA
AFDBYZ
AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE BILLINGS MT
605 AM MDT SUN MAR 29 2026
KEY MESSAGES
- WARM AND DRY AGAIN TODAY, WITH BREEZY WINDS ALONG THE WESTERN
FOOTHILLS.
- COLD FRONT MONDAY BRINGS BRISK NW WINDS, COOLER TEMPERATURES
AND A PERIOD OF RAIN/SNOW.
- AFTER A BRIEF WARMUP MIDWEEK, THERE IS INCREASING CONFIDENCE IN
ANOTHER PERIOD OF COOLER TEMPERATURES AND RAIN/SNOW LATE WEEK.
THIS IS LOOKING LIKE A MORE DYNAMIC WEATHER SYSTEM.
UPDATE
SKIES ARE CLEARING EARLY THIS MORNING IN THE WAKE OF A PASSING
SHORTWAVE. 850MB COLD ADVECTION IS NOSING INTO MUSSELSHELL AND
NORTHERN ROSEBUD, AND WOULD EXPECT MODEST NW WINDS (GUSTS IN THE
TEENS/20S?) ACROSS OUR NORTH AND EAST THIS MORNING. TODAY WILL
THEN BE MOSTLY DRY AND STILL QUITE WARM, BUT BY LATE AFTERNOON AND
EVENING ANOTHER WEAK WAVE IN THE ZONAL FLOW COMBINED WITH A
LITTLE INSTABILITY MAY BRING ISOLATED LIGHT RAIN SHOWERS OR
SPRINKLES TO MAINLY OUR WEST AND NORTH. BOUNDARY LAYER CONVERGENCE
DUE TO BACKDOORING EASTERLY WINDS MAY BE A FOCUS FOR LIGHT SHOWER
DEVELOPMENT. ALL OF THIS IS COVERED WELL IN THE FORECAST. LOOKING
TO MONDAY'S FROPA, THERE REMAINS A GOOD DEAL OF UNCERTAINTY WITH
ITS TIMING, WITH THE GFS BEING LATEST. IN FACT, THE 06Z GFS (AND
ITS ENSEMBLES) TRENDED A BIT SLOWER YET. A FEW EC ENSEMBLE MEMBERS
SHOW A SLOWER TIMING AS WELL. OVERALL THIS IS IMPOSSIBLE TO
DETERMINE AT THIS TIME. THE FROPA TIMING WILL IMPACT TEMPS AND
POTENTIAL GRASS FIRE CONCERNS ON MONDAY. LATER TIMING WOULD MEAN
WARMER/DRIER/WINDIER PRIOR TO THE FROPA, AND THIS COULD BE AN
ISSUE FOR SHERIDAN COUNTY AND PERHAPS FAR SOUTHEAST MT. THAT SAID,
THE 00Z HREF FOSBERG INDEX CLEARLY SHOWS THE ELEVATED FIRE RISK
SOUTH AND SOUTHEAST OF OUR FORECAST AREA. SOMETHING TO WATCH OVER
THE NEXT 24 HOURS. JKL
DISCUSSION
THROUGH SATURDAY...
TEMPERATURES WILL DROP INTO THE 30S TO LOWER 40S INTO THIS MORNING,
WITH POOR OVERNIGHT RELATIVE HUMIDITY RECOVERIES INTO THE
FOOTHILLS. WINDS WILL BE LIGHT OVERALL, WITH NORTHWEST WINDS
SPREADING OVER EASTERN AREAS THROUGH THE EARLY MORNING HOURS AS A
WEAK WAVE CROSSES THE REGION. TODAY WILL BRING ANOTHER DAY OF WELL
ABOVE NORMAL TEMPERATURES AND DRY CONDITIONS TO THE REGION WITH
HIGH PRESSURE IN PLACE. TEMPERATURES WILL BE NEAR TO SLIGHTLY
COOLER IN SOME LOCATIONS COMPARED TO SATURDAY. SOUTHWEST TO WEST
WINDS BEGIN SPREADING INTO THE WESTERN FOOTHILLS DURING THE
AFTERNOON WITH GUSTS INTO THE 20S AND 30S MPH COMMON AS MID LEVEL
WINDS INCREASE. LIVINGSTON COULD SEE A FEW GUSTS TO 40 MPH.
NORTHEAST TO EAST WINDS ASSOCIATED WITH A BOUNDARY MOVING IN FROM
THE NORTHEAST WILL KEEP THE STRONGEST WINDS CONFINED MAINLY TO THE
FOOTHILLS. A JET MAX NOSING IN THIS EVENING MAY BRING LOW CHANCES
(LESS THAN 25%) FOR SHOWERS ACROSS CENTRAL AND WESTERN AREAS.
WINDS WILL REMAIN BREEZY ALONG THE WESTERN FOOTHILLS TONIGHT INTO
MONDAY MORNING AS A SHORTWAVE MOVING THROUGH THE PAC NW
APPROACHES THE REGION. A STRONG COLD FRONT IS STILL PROGGED TO
MOVE THROUGH THE AREA DURING THE MORNING AND AFTERNOON ON MONDAY,
BRINGING BREEZY NORTHWEST WINDS (25 TO 45 MPH) AND COOLER
TEMPERATURES. A QUICK SHOT OF PRECIPITATION (40-90% CHANCE) WILL
OCCUR WITH AND BEHIND THE FRONT, IN THE FORM OF MOUNTAIN SNOW AND
RAIN CHANGING TO A RAIN/SNOW MIX AND WET SNOW OVER THE LOWER
ELEVATIONS. HIGHS LOOK TO RANGE FROM THE UPPER 40S OVER THE NORTH
TO THE 60S OVER THE SOUTH, WITH FALLING TEMPERATURES THROUGH THE
AFTERNOON. THERE MAY BE A BRIEF WINDOW FOR ELEVATED GRASS FIRE
CONCERNS OVER SHERIDAN COUNTY ON MONDAY, DEPENDING ON THE FRONTAL
TIMING AS SOME GUIDANCE BRINGS THE FRONT THROUGH DURING THE
MORNING, WHILE OTHERS BRING IT THROUGH THE AFTERNOON, ALLOWING FOR
A BIT WARMER AND DRIER CONDITIONS. PRECIPITATION DECREASES MONDAY
NIGHT INTO TUESDAY OVER THE LOWER ELEVATIONS, WITH MOUNTAIN SNOW
LINGERING THROUGH TUESDAY AFTERNOON. TEMPERATURES DOWN INTO THE
TEENS AND 20S WILL BE COMMON MONDAY NIGHT. PRECIPITATION AMOUNTS
LOOK TO RANGE FROM A FEW HUNDREDTHS OVER THE EAST, TO A TENTH OR
TWO, TO AS MUCH AS A HALF INCH FOR SOME AREAS OVER THE CENTRAL AND
WEST. PROBABILITIES FOR 0.25 INCHES OF LIQUID PRECIPITATION OR
MORE ARE ROUGHLY 30-80% OVER CENTRAL AND WESTERN ZONES, GREATEST
OVER THE MOUNTAINS AND FOOTHILLS. SEVERAL INCHES OF SNOW ARE
POSSIBLE IN THE MOUNTAINS, WITH A MODERATE TO HIGH CHANCE FOR 4 OR
MORE INCHES OF SNOW IN THE NORTHERLY UPSLOPE AREAS OF THE
SOUTHERN MOUNTAINS. THERE IS POTENTIAL FOR SOME LIGHT SNOW
ACCUMULATIONS OVER THE LOWER ELEVATIONS AS WELL WITH, A LOW TO
MODERATE CHANCE AT AN INCH OF SNOW, AND MODERATE TO HIGH CHANCES
INTO THE FOOTHILLS WHERE A COUPLE INCHES OF SNOW ARE POSSIBLE.
SHORTWAVE RIDGING IS PROGGED TO MOVE IN TUESDAY NIGHT INTO WEDNESDAY
BRINGING A BRIEF PERIOD OF WARMER AND DRIER CONDITIONS FOR THE
MIDDLE OF THE WEEK. SOUTHWEST FLOW INTO THE SOUTHERN MOUNTAINS
WILL KEEP LIGHT SNOW IN THE FORECAST FOR THE BEARTOOTH/ABSAROKAS.
HIGHS WILL RANGE FROM THE 40S ON TUESDAY, WARMING INTO THE 50S TO
LOWER 60S WEDNESDAY. HEADING INTO THURSDAY, LARGE SCALE TROUGHING
BEGINS MOVING INTO THE REGION BRINGING COOLER AND UNSETTLED
CONDITIONS THROUGH THE REMAINDER OF THE WEEK. ENSEMBLES INDICATE
THE POTENTIAL FOR A CLOSED LOW SCENARIO OR A SPLITTING TROUGH
SCENARIO. WHILE EACH COULD BRING PERIODS OF MOUNTAIN SNOW AND
RAIN/SNOW OVER THE LOWER ELEVATIONS, THE CLOSED LOW SCENARIO,
PARTICULARLY IF THE LOW TRACKS ACROSS WY, WOULD BRING A BETTER
POTENTIAL FOR PRECIPITATION. LOTS OF UNCERTAINTY REMAINS, BUT
THE SECOND HALF OF THIS WEEK BEARS WATCHING. STP
AVIATION
VFR CONDITIONS WILL PERSIST OVER THE NEXT 24 HOURS. WINDS ALONG
THE WESTERN FOOTHILLS WILL GUST 25-35 KNOTS FROM LATE MORNING TO
EARLY EVENING. A FEW LIGHT RAIN SHOWERS ARE EXPECTED IN THE LATE
AFTERNOON AND EVENING, MAINLY OVER THE WEST AND NORTH, BUT CLOUD
BASES WILL REMAIN HIGH (~10KFT AGL). JKL
PRELIMINARY POINT TEMP/POPS
TDY MON TUE WED THU FRI SAT
-------------------------------------------------------
BIL 071 041/056 025/046 028/060 039/060 032/046 029/055
0/U 18/O 71/B 11/B 37/W 75/W 32/W
LVM 069 044/051 022/044 028/059 038/051 027/043 027/053
1/N 18/O 51/B 13/R 58/W 65/J 21/B
HDN 072 038/058 024/048 027/063 037/063 031/046 026/053
0/U 16/O 71/B 11/B 36/W 86/W 32/W
MLS 064 036/055 022/042 028/059 037/058 031/042 025/049
0/U 24/R 40/U 10/B 24/W 66/W 32/J
4BQ 067 041/063 024/043 029/058 038/063 031/043 026/048
0/U 02/R 51/U 11/B 24/W 65/W 32/J
BHK 064 034/058 019/039 022/051 030/055 028/041 023/045
0/U 12/R 41/U 10/N 24/W 65/W 32/J
SHR 071 039/065 023/043 025/059 034/061 027/041 022/049
0/U 03/R 83/S 11/B 36/W 87/J 33/W
BYZ WATCHES/WARNINGS/ADVISORIES
MT...NONE.
WY...NONE.
WEATHER.GOV/BILLINGS
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